Marketplaces are great. On my Android phone I have, at my fingertips, a huge amount of applications that just work. Marketplaces provide us with a sense of security. To uninstall the app, there is guaranteed to be exactly one thing you must do. To install an app, there is exactly one way to install it. It is self contained, there are no dependencies I have to install. Configuration is non-existent, if at all. Discovering how to launch your app is straight forward. It just works.

Let's contrast that with a typical Linux system. I use Arch Linux. So, when I go to install an application, I use pacman -S someapp. And I cross my fingers and pray that it works. Usually it does. Sometimes I have to manually download and install things that aren't in this blessed "marketplace" of sorts. It's never as seemless as "closed" markets though. A linux application can do anything. It could corrupt my system(if I give it sudo), it could trash my home directory, it could install spam that I could never figure out how to uninstall.

These are two sides of a coin. They are naturally at ends. There isn't really a good way of curing these problems with Linux. Most people would say they aren't problems, but rather design choices(myself included).

Dependencies... how I miss thee

So, what's this all about? If you look on the Android Marketplace, iOS AppStore, or god forbid the Windows Store, you'll see a stark difference compared to Arch Linux's packages. And no, it's not the open source aspect.

If you want to search through a file in Linux, you'll probably use something like

cat somefile | grep 'something'

you'll use the cat utility to read the file in and pipe the contents to grep, where grep will search across the file for "something".

How do you do that on Android? Or Windows 8/RT?

Basically, you can't. At least, not in a good way. With Android, file managers is possible, and most of them include some basic searching capabilities, but you won't get the power of grep. You won't be able to do awesome shit like you can by combining the strengths of different applications.

If I wanted to write a file search utility for Android, I'd have to first build a sub-par file browser to navigate to the file, and then implement my actual search functionality.

Markets enforce master-of-none mentality

I once had a magnificent plan to port my scripting language to Android. How much work would that require?

File browsing/saving/loading

Text editor (syntax highlighting, searching, etc. More than just a text box)

My programming language

And that's just the start. If I want to provide APIs in my language to search in files, I have to implement that. If I want network access, I have to provide that. There is no netcat, or grep that people could utilize instead of my sub-par APIs.

Why netcat doesn't exist in markets

If you wanted to implement a netcat utility in any marketplace, it'd be fairly pointless. The power of netcat comes from being able to pipe it to other places that the original authors never even dreamed of. What's that, you want to make a TCP/IP proxy?

nc -l -p 8080 | nc example.com 80

You want something that can encrypt a file and send it off somewhere?

openssl aes-256-cbc -salt -e < file-to-transfer | nc example.com 9999

How would you do this in a marketplace application? Sure, maybe you could cobble together some solution like finding a dedicated TCP proxy. And then finding a file encrypter and a TCP/IP program that can send files... but this requires that someone developed such an application beforehand.

You can't just create some general purpose utility. You must create some "multi" purpose utility where you came up with all of the interesting use cases you could and implement them. If you missed one, then there just isn't a solution to that problem. There is no way to combine your program and some other program to solve the problem. It's all or nothing.

It's not just markets

If you notice, desktop Windows does this to a certain extent as well. It's I/O redirection is downright terrible. (although I hear Powershell is nice) This is probably why you see all-in-one applications everywhere. Linux has a general "air" about it that encourages you to make things modular and enable the utilization of other tools where possible.

However, marketplaces is the only place where this is actually enforced. Windows 8 has extremely limited IPC functions. Oh, you gave me a (very limited) search API that works across every application, big whoop. Windows 8 especially enforces it. Did you know that you can't make a general purpose text editor in Windows 8? Impossible. There is no way to open every file with a single application. They enforce you to declare which file extensions you'll be allowed to edit (and no, * doesn't work).

Finally, the bugs

Have you ever encountered a bug in a walled-garden application? Of course you have. Would you say you encounter them more than on desktop application? Probably. Developers can't worry about only one thing because if they don't implement it, then their application can't do it. You get a feature request in your netcat-want-to-be for sending text on-demand instead of files. Now you have to implement some kind of text editor. Now some people want to be able to return an automated response that returns the current date and time. Yea, good luck with keeping up with the wishes of your users.

Developers can't just worry about the one thing they do good. They also have to worry about all the things people might want to combine to make your application more useful. This is why I believe that most market applications have more bugs than their counterparts in desktop operating systems.

For the picky

Yes, I know I probably have some false assumptions, but I'm not far off. I'm no pro in Android and such. It's probably possible to do some rudimentary IPC and maybe even some kind of dependency stuff... but it's not the norm, and I know it's probably not easy for you OR the end user.